No-glare headlight.



E. BRUNS. N0 GLARE HEADLIGHT.

APPLICATION FILED AUG-14. 1916.

I Patented Mar. 6, 1917.

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' UNITED STATES PATENT curios.

EDWARD mums, or PORTLAND, OREGON.

NO-GLARE HEADLIGHT.

otherwise arranged to eliminate any glare.

The .object of my invention is to break up and spread out, in short, todisperse the projectedrays of the lamp in a lateral direction through the medium of the lens, in this way using substantially the full illuminating'power of the lamp, but avoiding all strong or blinding rays.

I attain my object by a lens the entire surface of a portion of which is covered with narrow, contiguous, parallel ribs of prismatic cross section.

The details of construction of my lens and the theory of its operation are hereinafter fully described and shown in the accompanying drawings, in which:

. Figure 1 shows, in diagrammatic form, the housing of a headlight, understood to include a parabolic reflector, it also shows the lamp and'a diagrammatic section of my lens on the line 1'1 of Fig. 2;

Fig. 2 is a rear elevation of my lens, more or less. diagrammatic, and as viewed when looking in the direction pointed by the arrow;

Fig. 3 is a partial section, drawn on an enlarged scale, along the line 3 of Fig. 2; and

Fig. 4 is an exaggerated diagrammatic cross-section showing more clearly the crosssectional structure of said prismatic ribs.

(1 represents the lens in its entirety. The lens is of the convex-concave type and of a diameter suitable to the particular lamp for which it is to be used.

In Fig. 1, 7) represents a parabolic reflector of the usual type, and c is a lamp, or source of light, located at the focal center, the rays of the lamp being projected forward in a solid beam of parallel elements.

The lens is made of molded opalescent glass, the inner or concaved surface being Specification of Letters Patent. 7

Application filed August 14, 1916. Serial No. 114,904.

Patented Mar. 6, 191 "7.

finished as follows: The portion (Z is ground or sanded so as to be merely translucent, in-

stead of transparent. The entire surface of the portion e 1s covered with narrow, contiguous, parallel ribs as f, of'prismatic crosssection, as diagrammatically illustrated in an exaggerated form in Fig. 4. The ribs are arranged perpendicular to' an imaginary diameter dividing said translucent portion from said rib portion of the lens. By reason of'such construction the rays transmitted through the prismatic ribs are dispersed in a lateral direction, a large number of them being projected directly forward, and so the whole space in front of the lens is illuminated effectively, very little ofthe illuminating power ofthe lamp being lost. But

the illumination will be withiiut any glare indeed one may look directly at the light from any point in front of ,the lens. The

described result is due to the fact that some of the rays will be projected directly forward, as indicated by the line it, others approximately as indicated by the line i, and the rays diagrammatically illustrated by j, being given still other deflections, so that the whole volume of light will be evenly distributed.

In practice I have found that making the ribbed surface-e of the lens with said ribs running twenty to the inch brings about very satisfactory results. And I also deem it preferable that the prismatic ribs be made, as diagrammatically shown in Fig. 4, instead of having straight prismatic faces.

Preferably the defining line represented by between the translucent (d) and ribbed (0) surfaces of the lens, is symmetrically curved, so that its central portion extends lower than and coversthe source of light, and its side portions flare outwardly to points slightly above the horizontal diameter of the lens.

I prefer to make mylens of rolled white flint glass. sults are obtained by making the lens of a curvature similar to that shown in Fig. 1; e. 9., with a central portionabout one sixth of the diameter of the lens0f very flat curvature, surrounded by a zone of a considerably sharper curvature which blends into a marginal zone of reverse curvature, the latter ending in an approximately flat surface to permit the lens to fit readily in any standard automobile lamp. The radii of these zones of my lens are given in Fig. 1.

I have also found the best re- I claim:

1. In a headlight, the combination of a lamp, a hood therefor including a parabolic reflector and a lens covering the front of such hood, said lens having a portion of its surface translucent and the entire remaining ranged perpendicular to an imaginary diameter dividing said translucent portion from said rib portion of the lens.

3. A lens made with an approximately flat middle portion, being convex from such portion, a portion'of the lens being covered with narrow, contiguous parallel ribs of prismatic cross section, said ribbed portion of the lens sxtending V form below the center of the ens.

4. A lens made with an approximately flat middle portion, being convex from such portion, a portion of the lens being covered with narrow, contiguous parallel ribs of prismatic cross section, said ribbed portion of the lens extending V form below the center of the lens, and the remaining .portion of the lens being translucent.

5. A lens made with an approximately fiat middle portion, being convex from such portion, and reversely curved at its margin, a

portion of the lens being coveredwith narrow, cont guous parallel ribs of prismatic .1

cross sectlon, and the remaining portion of the lens being translucent.

6. A lens made with an approximately flat middle portion, being convex from such por tion, and reversely curved at its margin, a

portion of the lens being covered with narrow, contiguous parallel ribs of prismatic cross section, said ribbed portion of the lens extending V form below the center of the lens, and the remalning portion of the lens being translucent.

7. A lens made with an approximately fiat middle portion, being convex from such portion, and reversely curved at its margin, the latter terminating in a more or. less flat surface; a portion of the lens being covered with narrow, contiguous parallel ribs of prismatic cross section, said ribbed portion of the lens extending V form below the center of the lens, and the remaining portion of the lens being translucent. r

1 8. In a headlight, the combination of a lamp, a hood therefor including a parabolic reflector and a lens covering the front of such hood, said lens'having the upper portion of its surface covered with verticaL'narrow, contiguous, parallel ribs of prismatic cross-section, such ribbed portion having its central portion extending slightly lower than and covering the source of light and curving upwardly at the sides to points slightly above the horizontal diameter of the lens, and the entire remaining portion of its surface being translucent.

- EDWARD BRUNS. 

